DETERMINATION OF RETINOIDS IN COSMETICS 499 retinoic acid. Concentrations of all-trans-retinol ranged from 59 μg/g to 21817 μg/g. Concentrations for all-trans-retinyl palmitate ranged from 15 μg/g to 14984 μg/g. Retinoid concentrations and identity were found to be consistent with the label informa- tion in 23 products (80%). One product, without any listed ingredients, was found to contain retinyl palmitate at 563 μg/g. Another product that listed only retinyl palmitate on the label was found to contain all-trans-retinol (139 μg/g) in addition to all-trans-reti- nyl palmitate (14984 μg/g). This is possibly due to the hydrolysis of the retinyl palmitate during manufacturing or during storage. Two products were found to contain retinyl palmitate in addition to retinol, the listed ingredient. The most likely explanation for this is the presence of retinyl palmitate in the retinol ingredient as an impurity. Alternatively, retinyl palmitate may have been used as a partial substitute for retinol. Two other prod- ucts, although labeled to contain both retinol and retinyl palmitate, were found to contain only retinol in one product, and only retinyl palmitate in the other product. CONCLUSIONS In this report, a rapid method for the determination of retinoic acid, retinol, and retinyl palmitate in consumer cosmetic products is described. The method allows determination of all retinoids commonly used as cosmetic ingredients. Twenty-nine consumer cosmetic products, including anti-wrinkle, anti-aging, skin renewal, line removal, skin-whitening, moisturizing, and skin-cleansing preparations, were analyzed. Seventeen of the surveyed products included retinol on the ingredient label, and four listed retinyl palmitate. Six included both retinol and retinyl palmitate. One product did not indicate the presence of either retinol or retinyl palmitate. Overall, the retinoids found in the products agreed with retinoids identifi ed as ingredients on the labeling of the product. Retinoic acid was not found in any of the analyzed products. The range of concentrations determined for retinol and retinyl palmitate was found be generally ≤1%, consistent with earlier reports (7,8). The analytical method described here is appropriate for use in larger surveys of retinoids in cosmetic products and can provide data needed for estimating exposure levels to these commercially important cosmetic ingredients. REFERENCES (1) C. E. Bloch, Clinical investigation of xeropthalmia and dystrophy in infants and young children (xe- rophthalmia et dystrophia alipogenetica), J. Hyg., 19, 401–404 (1921). (2) S. Mori, The changes in para-ocular gland which follow the administration of diets low in fat-soluble A with notes of effect of same diets on the salivary glands and the mucosa of the larynx and trachea, Bull. Johns Hopkins Hosp., 33, 357–358 (1922). (3) S. B. Wolbach and P. R. Howe, Tissue changes following deprivation of fat-soluble A vitamin, J. Exp. Med., 43, 753–777 (1925). (4) P. Fu, Q. Xia, M. D. Boudreau, P. C. Howard, W. H. Tolleson, and W. G. Wamer, Physiological role of retinyl palmitate in the skin, Vitam. Horm., 75, 223–256 (2007). (5) A. R. Brecher and S. J. Orlow, Oral retinoid therapy for dermatologic conditions in children and ado- lescents, J. Am. Acad. Dermatol., 49, 171–182 (2003). (6) C. C. Geilen, B. Almond-Roesler, and C. E. Orfanos, “Therapeutic Uses of Retinoids in Skin Disease,” in Vitamin A and Retinoids: An Update of Biological and Clinical Applications, M. A. Livrea, Ed. (Birkhäuser Verlag, Basel, 2000), pp. 251–259. (7) Cosmetic Ingredient Review, Final report on the safety assessment of retinyl palmitate and retinol, J. Am. Coll. Toxicol., 6, 279–320 (1987).

JOURNAL OF COSMETIC SCIENCE 500 (8) In a memorandum dated June 13, 2005 from Wilbur Johnson, Jr., Senior Scientifi c Analyst, to the CIR Expert Panel, Mr. Johnson notes that current-use concentration data from the cosmetics industry indicate that retinol and retinyl palmitate are being used at concentrations up to 2%. Information found on the CIR’s website now indicates that retinol and retinyl palmitate are safe as used in cosmetics up to 5%. (9) J. J. Yourick, C. T. Jung, and R. L. Bronaugh, In vitro and in vivo percutaneous absorption of retinol from cosmetic formulations: Signifi cance of the skin reservoir and prediction of systemic absorption, Toxicol. Appl. Pharmacol., 231, 117–121 (2008). (10) L. S. Baumann, Safety considerations for retinol use in cosmetic products, Cosmet. Dermatol., 18, 9–13 (2005). (11) G. J. Nohynek, W. J. A. Meuling, W. H. J. Vaes, R. S. Lawrence, S. Shapiro, S. Schulte, W. Steilung, J. Bausch, E. Gerber, H. Sasa, and H. Nau, Repeated topical treatment, in contrast to single oral doses, with vitamin A-containing preparations does not affect plasma concentrations of retinol, retinyl esters or retinoic acid in female subjects of child-bearing age, Toxicol. Lett., 163, 65–76 (2005). (12) K. L. Penniston and S. A. Tanumihardjo, The acute and chronic toxic effects of vitamin A, Am. J. Clin. Nutr., 84, 191–201 (2006). (13) R. E. Davies and P. D. Forbes, Retinoids and photocarcinogenesis: A review, J. Toxicol. Cut. Ocular Toxi- col., 7, 241–253 (1988). (14) Anonymous, Request for Comments on Substances Nominated to NTP, Federal Register, 65, 75727– 75730 (2000). (15) S. Scalia, A. Renda, G. Ruberto, F. Bonina, and E. Menegatti, Assay of vitamin A palmitate and vitamin E acetate in cosmetic creams and lotions by supercritical fl uid extraction and HPLC, J. Pharmaceut. Biomed. Anal., 13, 273–277 (1995). (16) C. Ceugniet, L. Loetitia, N. L. De Viguerie, H. Jammes, N. Peyrot, and M. Riviere, Single-run analysis of retinal isomers, retinol and photoxidation products by high-performance liquid chromatography, J. Chromatogr. A, 810, 237–240 (1998). (17) L.-H. Wang and S.-H. Huang, Determination of vitamins A, D, E, and K in human and bovine serum, and β-carotene and vitamin A palmitate in cosmetic and pharmaceutical products, by isocratic HPLC, Chromatographia, 55, 289–296 (2002). (18) L.-H. Wang, simultaneous determination of retinal, retinol and retinoic acid (all-trans and 13-cis) in cosmetics and pharmaceuticals at electrodeposited metal electrodes, Anal. Chim. Acta, 415, 193–200 (2000). (19) N. Failloux, I. Bonnet, M.-H. Baron, and E. Perrier, Quantitative analysis of vitamin A degradation by Raman spectroscopy, Appl. Spectroscopy, 57, 1117–1122 (2003). (20) R. Flores-Perez, A. K. Gupta, R. Bashir, and A. Ivanisevic, Cantilever-based sensor for the detection of different chromophore isomers, Anal. Chem., 79, 4702–4708 (2007). (21) L. R. Snyder, J. J. Kirkland, and J. L. Glajch, Practical HPLC Method Development, 2nd Ed. (John Wiley & Sons, New York, 1977), pp. 689–695. (22) A. B. Barua and J. A. Olson, “Vitaman A and Carotenoids,” in Modern Chromatographic Analysis of Vita- mins, 3rd Ed., A. P. De Leenheer, W. E. Lambert, and J. F. Van Bocxlaer, Eds. (Marcel Dekker, New York, 2000), pp. 1–74. (23) B. Idson, Vitamins in cosmetics, an update: I. Overview and vitamin A, Drug Cosmet. Ind., 146, 26–28, 91 (1990). (24) The use of BHT and EDTA as antioxidants in cosmetics is well known. See for example the respective entries for BHT and EDTA in Wikipedia at www.wikipedia.org.